As the technology of low temperature poly-silicon (LTPS) in thin-film transistor (TFT) advances and the characteristic of ultra-high carrier mobility of the LTPS semiconductor, the corresponding peripheral integrated circuit of the panel has drawn much attention. Additionally, many people put effort in the research in relation to system on panel (SOP) and make it available. However, because of the ultra-high carrier mobility of the LTPS, it is much worse than A-Si in terms of electric leakage. Hence, it is crucial to solve the problem of electric leakage in the LTPS design.
As shown in FIGS. 1 and 2, FIG. 1 is a flow chart of a manufacturing method of a TFT array substrate of current technology and FIG. 2 is a process flow diagram of the manufacturing method of the TFT array substrate based on the current technology. In the current technology, the manufacturing method of LTPS-TFT having the bottom gate structure comprises the following steps:
S10, forming a gate pattern layer 41 on a substrate 40;
S11, forming a gate insulating layer 42 on the gate pattern layer 41;
S12, forming a patterned poly-silicon layer 43 on the gate insulating layer 42, the patterned poly-silicon layer 43 being connected to the gate insulating layer 42;
S13, forming a heavily doped source area 431 and a heavily doped drain area 432 on two sides of the patterned poly-silicon layer 43 respectively;
S14, adopting a mask to form a lightly doped source area 434 on the inner side of the heavily doped source area 431, and to form a lightly doped drain area 433 on the inner side of the heavily doped drain area 432, a channel area being between the lightly doped source area 434 and the lightly doped drain area 433;
S15, forming a separation layer 44 on the patterned poly-silicon layer 43; and
S16, forming source and drain pattern layers 45 on the separation layer 44 and making the source and drain pattern layers 45 be connected with the patterned poly-silicon layer 43.
In the manufacturing method, in step S14 where the lightly doped area is formed, it is required to specially design a mask to block the area outside the region for the lightly doped area. This therefore increases the cost of the method.